The present invention relates to a plate positioning and feeding system for a punch comprising a positioning station disposed upstream of the punch and including positioning means for positioning a plate with respect to a pair of orthogonal axes, and at least one feed device actuated by drive means controlled by a numerical control. The feed device including gripping means gripping the plate and advancing it to the punch in a cycled manner corresponding to cycling of the punch.
Such systems are used to feed plates, for example of steel or aluminum sheet material, to a punch which punches out a predetermined number of blanks from each plate. By means of the feed, devices each plate is moved step by step through the punch and is subjected to punching steps while it is stationary.
Various feeding systems have become known and are shown for example in U.S. Pat. No. 4 382 395, German Patent 34 37 642, European Patent Specification 92 113 561.2 and German Patent 38 41 683.
The punching of the plates should be performed such that as little material as possible will remain in the punched plates in order to save material. On the other hand it is to be avoided that the punching tools punch through the edges of the plates. Accordingly, it is imperative that the plates be advanced as precisely as possible. The prior art feed systems do not allow for precise positioning and/or require sophisticated and costly control systems for precise positioning of the plates.
It has become known to cut the plates from continuous stock material by means of plate scissors. Such cutting results in variations of the plate length and the angularity of the cut edges of the plates within the manufacturing tolerances.
It is an object of the present invention to provide a plate positioning and feeding system for a punch, which ensures precise feeding and advancing of the plates. A further object of the present invention is to provide a plate positioning and feeding system for a punch, which punches the plates so that residual meshes of minimum material result and punching through the trailing and leading edges of the plates is avoided.